Chuck



NOV. l l 7 lili! www@ A. URQUHART CHUCK Filed April 28 H Hl w LI'- "g U 2 /NVUWd/P Am @wg n I CTI Patented Nov. lll, i924.

.ALEXANDER URQUHART,

CON lEGTlC'UT.

or nanna,

CHUCK.

Vl-lpplication filed April 28, 1923. Serial No. 685,321.

To all whom t may concern# lBe it known that l, ALEXANDER URQU- HART, a citizen of the United States, residing` at Derby, in the county of New Haven and State ot' Connecticut, have invented a new and useful Improvement in Chucks, of which the lollowing` is a specilication.

This invention relates to those chucks which have but 'a relatively small opening and closing range and that are adapted to be applied to engine lathes, turret lathes, screw machines, grinders, boring mills, drill presses and similar machine t'ools, for receiving and holding pieces of work ot' sul stantially uniform size, interchangeable bushings oi" various capacities for pieces of different sizes and character being provided for one body. Such chucks while particularly adapted to hold rods, bars, and tubes, are capable of holding other classes of stock and operating tools.

rl`he object of the invention is to provide a very simple, cheap and durable construction which can be easily and quickly opened for releasing the piece which is held, and powerfully closed for gripping a piece, the contractive action of the chuck being caused in such manner that the work will be centered and turn true and the strain incident to the resistance offered by the work will tend to increase the grip of the chuck on the piece being held.

.ln attaining this object a hollow sleeve, slitted so that it may be 'radially contracted, is rotatably litted but longitudinally held within a `hollow cylindrical body. On the exterior of the lsleeve and interior of the body are complementary spiral grooves of such shape and occupied by means ot such iorin that when the body is rotated one way with relation to the sleeve said means are forced into` a position between the parts which causes `the sleeve to contract, and when the body is rotated in the opposite direction saidnieans assume a posioion' which permits the sleeve to expand to normal size.

ln the accompanying drawings Fig. l shows a'sidefview with a part 'of the bod cut in central longitudinal section, of chuck that embodies the invention. Fig'. is a view of one endet the chuck. Fig'. is a view looking toward the other end. Fig. 4 is a section of ran end of the chuck on the plane indicated by the dotted line -fl on Fig. 2, with a reducing'bushing held, in the (Lowe-91d sleeve. Fig. vis an end view of the chuck provided with a handwheel lor convenience o'lf operation. 6 is a side view of the end or" the chuckand hand wheel, with the riin ot the wheel cut away to show means provided for clamping` the wheel on the body.- Fig. 7' shows a section of one end of the body and side view of the sleeve with a modilied arrangement oi spiral grooves.

The body l of the chuck is a hollow cylinder and the sleeve 2 is' a hollow cylinder fitted to rotate but held against longitudinal movement in the body. rlhe walls ol' the body are solid, that is. they are not expansible, while the walls ,oli the sleeve within the body are slitted in such manner that they can be contracted in order to reduce the bore ot the sleeve. y At one'end the sleeve has an enlarged head 3 which is of course also slitted. Fastened to the inside 'tace near the edge of the head are plates l which have danges 5 that extend into a `groove 6 around the body for the purpose of preventinv relative endwise movement of the parts. Balls 7 are desirably placed between this end otl the body and the inside oi the head to relieve the longitudinal thrust of the parts when in operation. Fastened to the other end of the body is al ball retaining ring` S.

A spiral groove 9 is cut around the exterior of the slitted sleeve and a spiral groove 10 is cut around ther interior et the solid body.v These grooves are complementary and they may be either right-hand or lett-hand spirals as desired. ln the form illustrated in Fig. l the groove in the sleeve is approximately semi-circular in cross section and the groove in the body has a weeg@ shaped bottom. .ln the forni shown in Fig. 7 the groove in the body is semi-circular while the groove in the sleeve is wedgeshaped in cross section. Completely Fillingthe grooves around the slitted sleeveT with substantially half in the sleeve and half in the body, are balls 1l, practically shown and described in Patent .#1,464,551 granted to me August 14, 1923. i

Rotating the body, of the form lirst shown. in one direction with relation to the sleeve has the eect of crowding the balls into the shallower portions ot the groove in the body and this causes the balls to exert an inward pressureI uniformly around the sleeve so that the bore of the sleeve will be contracted. Turning the body lof this torni in the opposite direction carries the balls into the deeper portions of the groove in the body and permits the sleeve to expand. In the second form rot-ating the body in one direction has the effect of crowding the balls into the shallower portions of the groove in the sleeve and this causes them'to exert an inward contracting pressure on the sleeve. Turning the body in the opposite direction of this form carries the balls into the deeper portions of the groove in the sleeve and allows the sleeve to expand. The spiral pitch of the grooves is desirably in such direction that the rotatable back pressure on any piece of work that is held in the sleeve, caused by the cutting action of a tool, or the pressure on any tool that is in the sleeve, caused by its work, will tend vto contract the sleeve onto the worker the tool shank. c

A pin 12 may be screwed into the head or one of the plates fastened to the head,

i and a pin 13 may be screwed into the body,

in such relation that the body will not turn backward beyond a definite point.

To enable the chuck to hold smaller work than the bore of the sleeve itselic will hold, a bushing 15, ('Figjt) having an outside diameter that will just tit into the bore of the sleeve and which is slitted so that it may be contracted, may be placed in the sleeve. This bushing which can have any desired bore may be retained in place by a pin 16 located in a socket 17 in the head of the sleeve. The inner end of the pin is adapted to enter a groove 18' around the bushing. A spring 19 tends to push this pin out. l/Vhen it is desired to fasten a bushing in the sleeve the pin is pushed in and turned by a screw driver or other tool so that its head will engage back of a stud 20, a slot 14 being made through the head of the pin so that when turned to oneposition it can be pushed in or allowed'to spring out past the stud.

For the purpose of facilitating' the opening and closing of the chuck a hand wheel 21 may be mounted to turn loosely on the body. This wheel is located adjacent to the yhead of the sleeve in such position that the pin 12 will project from the sleeve head into a recess 22 in the hub of the hand wheel. rlhe end walls 23 of the recess in the hub are adapted to engage V*the pin 12 and through it turn the sleeve relatively to the body which is held against rotationat this time. The hub of this hand wheel is slitted so that it may be contracted and clamped to the body for holding the chuck closed on a piece of work. For this purpose the hub of the hand wheel adjacent to the slit is provided with lugs 24 and 25, through the former and into the latter of which extends a bolt 26 provided with nuts 27 by means of which its longitudinaly position may be adybeing held therein.

justed. The head 28 of the bolt is drilled to take the eccentric shaft 29 which is pivoted in the lugs and provided with a handle 30 by `means of which it may be turned. Turning the handle one way contracts the hub and clamps the hand wheel to the body. Turning the handle oppositely frees the wheel on the body. lVhen the chuck has been closed by turning the hand wheel on the body, through the en gagement of a wall 23 of the recess in the hub with the pin l2, and the wheel is then locked to the body the sleeve cannotturn back so as to loosen its hold on the article The hand wheel provides a very convenient operating means in case the article held by the chuck cannot bc conveniently grasped when the chuck is being tightened on it or loosened from it. The pitch of the spiral and the wedge angle of the ball grooves are so related that an extremely powerful contractive force can be developed by the application of `a small amount of power to and little movement of the hand wheel. If a heavy cut is taken the resistance of the work to the action of the tool is in such direction that the pressure tends to increase the hold of thesleeve on the part which it is holding. As the inward pressure of the balls is uniformly distributed about the sleeve the sleeve is contracted in such a way that it will normallyhold the work centrally true.

The invention claimed is LA chuck comprising a body, a contractile sleeve rotatably fitted within and held from longitudinal movement with relation to the body, a spiral groove formed in the exterior ol the sleeve, a spiral groove formed in the interior of the body, and means eX- tending into the body and sleeve loosely occupying said grooves and adapted to be forced radially inward and contract the sleeve when the body is rotated in one direction with relation to the sleeve.

2. A chuck comprising a body, a slitted sleeve rotatably tted within and held from longitudinal movement with relation to the body, complementary spiral grooves in the interior of the body and on the exterior of the sleeve, and means extending into the body and sleeve loosely occupying said grooves and adapted to be forced radially inward and contract the sleeve when the body is rotated in one direction with relation to the sleeve.

3. A chuck having a body, avsection of the interior of which is provided with a spiral groove that has a tapered' bottom, a sleeve rotatably fitted in the body and provided on its exterior with a semi-circular spiral groove, and balls occupying said grooves and adapted when the body is rotated in one direction with relation to the sleeve to contract the sleeve.

et. A chuck having a body, a section on the interior of which is provided With a spiral groove that has a tapered bottom, a sleeve rotatably litted in the body and provided on its exterior with a semi-circular spiral groove, and means arranged in said grooves and adapted to contract the sleeve when one part is given a rotative movement relative to the other part.

5. A chuck comprising a body, a contractile sleeve rotatably fitted in and held from longitudinal movement with relation to the body, complementary spiral grooves in the interior of the body and on the exterior of the sleeve, means extending into the body and sleeve and loosely filling said grooves to affect the contracting of the sie-eve when the body is rotated in one direction with rela-tion to the sleeve, and stop pins projecting from the sleeve and body to limit the backward movement of the body with relation to the sleeve.

6. A chuck comprising a body, a contractile sleeve rotatably fitted within the body, complementary spiral grooves in the interior of the body and on the exterior of the sleeve, means located in said grooves to allect the contraction of the sleeve when the body-is rotated in one direction with relation to the sleeve, stop pins projecting from the sleeve and body to limit the backward movement of the latter with relation to the former, and a hand Wheel arranged to engage the pin projecting from the sleeve for turning the sleeve.

7. A chuck comprising a body, a contractile sleeve rotatably fitted Within and held from longitudinal movement With relation to the body, a spiral groove formed in the interior of the body, a spiral groove formed on the exterior of the sleeve, and balls ex-y tending into the body and sleeve and filling these grooves and adapted to contract the sleeve when the body is rotated in one direction with relation to the sleeve.

8. A chuck having a body with an interiorly threaded section, a contractile sleeve having an exteriorly threaded section rotatably .fitted in and held from longitudinal movement with relation to the body, balls filling the thread grooves, and a hand Wheel arranged to turn the body With relation to the sleeve.

9. A chuck having a body with an interiorly threaded sec-tion, a contractile sleeve having an exteriorly threaded section rotatably fitted in and held from longitudinal movement vvith relation to the body, contracting means occupying the thread grooves, a hand Wheel arranged to rotate the sleeve with respect to the body, and means for clamping the hand wheel to the body.

10. A chuck comprising a body, a contractile sleeve rotatably mounted Within and held from longitudinal movement with relation to the body, complementary spiral grooves in the interior of the body and on the exterior of the sleeve, balls located in said grooves and adapted to contract the sleeve Whe-n the sleeve is turned in one di rection With relation to the body, a hand Wheel rotatably mounted on the body, and means for clamping th-e hand Wheel to the body.

ALEXANDER URQUHART. 

